Audiences will be able to watch live online and submit questions in real-time. The pilot is expected to air in January.
Questions can be sent in either using Twitter and the hashtag #WT4, or via an on-site facility which will not only let viewers submit questions, but also see what others are asking, and engage in an online poll around the subject.
The interviewer, a member of the Channel 4 News presenting team, will only ask questions posed by the online audience, Anna Doble, head of online at Channel 4 News told Journalism.co.uk.
The first video is expected to be around 20 minutes in length, and the aim is to "bring the audience on social media right into the studio", Anna Doble, head of online at Channel 4 News told Journalism.co.uk, although she added that it will be a "slightly different set". There will also be an audience watching in the studio.
After being livestreamed on the Channel 4 News websites, the full video will be available both on the site and via 4OD, Channel 4's on-demand service.
While the first pilot will feature just one interview, the team will reflect on the format after going live this week and "see how it works", Doble said. And while the idea is that the video will last around 20 minutes, the team are remaining flexible. Therefore if the conversation warrants longer than the 20 minutes predicted, "we can keep streaming if we want", she added.
Update: The first pilot of What the Four will now run in January.